Evaluation of the ability of calcite, bentonite and barite to enhance oil dispersion under arctic conditions.

A test program was conducted at laboratory and pilot scale to assess the ability of clays used in drilling mud (calcite, bentonite and barite) to create oil-mineral aggregates and disperse crude oil under arctic conditions. Laboratory tests were performed in order to determine the most efficient conditions (type of clay, MOR (Mineral/Oil Ratio), mixing energy) for OMA (Oil Mineral Aggregate) formation. The dispersion rates of four crude oils were assessed at two salinities. Dispersion was characterized in terms of oil concentration in the water column and median OMA size. Calcite appeared to be the best candidate at a MOR of 2:5. High mixing energy was required to initiate OMA formation and low energy was then necessary to prevent the OMAs from resurfacing. Oil dispersion using Corexit 9500 was compared with oil dispersion using mineral fines.

Detection of coffee adulteration with soybean and corn by capillary electrophoresis-tandem mass spectrometry.

The detection of coffee adulteration with soybean and corn by capillary electrophoresis-tandem mass spectrometry was accomplished by evaluating the monosaccharides profile obtained after acid hydrolysis of the samples. The acid hydrolysis, using H2SO4 as a catalyst, increases the ionic strength of the sample impairing the electrophoretic separation. Therefore, Ba(OH)2 was used to both neutralize the medium and reduce the content of sulfate by precipitation of BaSO4. The best separation of nine determined monosaccharides (fucose, galactose, arabinose, glucose, rhamnose, xylose, mannose, fructose and ribose) plus inositol as internal standard was obtained in 500 mmol·L-1 triethylamine, pH 12.3. The monosaccharides are separated as anionic species at this pH. The proposed method is simple, fast (<12.0 min), present linear calibration curves (r2 = 0.995), and relative standard deviation for replicate injections lower than 5%. The LOQ for all monosaccharides was lower than 0.01 mmol·L-1, which is in accordance with the tolerable limits for coffee. Principal component analysis (PCA) was used to evaluate interrelationships between the monosaccharide profile and the coffee adulteration with different proportions of soybean and corn. Fucose, galactose, arabinose, glucose, sucrose, rhamnose, xylose, mannose, fructose, and ribose were quantified in packed roast-and-ground commercial coffee samples, and differences between adulterated and unadulterated coffees could be detected.

An Imaging and Histological Study on Intrahepatic Microvascular Passage of Contrast Materials in Rat Liver.

Background. Lipiodol has been applied for decades in transarterial chemoembolization to treat liver malignancies, but its intrahepatic pathway through arterioportal shunt (APS) in the liver has not been histologically revealed. This rodent experiment was conducted to provide evidence for the pathway of Lipiodol delivered through the hepatic artery (HA) but found in the portal vein (PV) and to elucidate the observed unidirectional APS. Methods. Thirty rats were divided into 5 groups receiving systemic or local arterial infusion of red-stained iodized oil (RIO) or its hydrosoluble substitute barium sulfate suspension (BSS), or infusion of BSS via the PV, monitored by real-time digital radiography. Histomorphology of serial frozen and paraffin sections was performed and quantified. Results. After HA infusion, RIO and BSS appeared extensively in PV lumens with peribiliary vascular plexus (PVP) identified as the responsible anastomotic channel. After PV infusion, BSS appeared predominantly in the PV and surrounding sinusoids and to a much lesser extent in the PVP and HA (P < 0.001). Fluid mechanics well explains the one-way-valve phenomenon of APS. Conclusions. Intravascularly injected rat livers provide histomorphologic evidences: (1) the PVP exists in between the HA and PV, which is responsible to the APS of Lipiodol; and (2) the intrahepatic vascular inflow appears HA-PVP-PV unidirectional without a physical one-way valve, which can be postulated by the fluid mechanics.

Co-precipitation of radium with barium and strontium sulfate and its impact on the fate of radium during treatment of produced water from unconventional gas extraction.

Radium occurs in flowback and produced waters from hydraulic fracturing for unconventional gas extraction along with high concentrations of barium and strontium and elevated salinity. Radium is often removed from this wastewater by co-precipitation with barium or other alkaline earth metals. The distribution equation for Ra in the precipitate is derived from the equilibrium of the lattice replacement reaction (inclusion) between the Ra(2+) ion and the carrier ions (e.g., Ba(2+) and Sr(2+)) in aqueous and solid phases and is often applied to describe the fate of radium in these systems. Although the theoretical distribution coefficient for Ra-SrSO4 (Kd = 237) is much larger than that for Ra-BaSO4 (Kd = 1.54), previous studies have focused on Ra-BaSO4 equilibrium. This study evaluates the equilibria and kinetics of co-precipitation reactions in Ra-Ba-SO4 and Ra-Sr-SO4 binary systems and the Ra-Ba-Sr-SO4 ternary system under varying ionic strength (IS) conditions that are representative of brines generated during unconventional gas extraction. Results show that radium removal generally follows the theoretical distribution law in binary systems and is enhanced in the Ra-Ba-SO4 system and restrained in the Ra-Sr-SO4 system by high IS. However, the experimental distribution coefficient (Kd') varies widely and cannot be accurately described by the distribution equation, which depends on IS, kinetics of carrier precipitation and does not account for radium removal by adsorption. Radium removal in the ternary system is controlled by the co-precipitation of Ra-Ba-SO4, which is attributed to the rapid BaSO4 nucleation rate and closer ionic radii of Ra(2+) with Ba(2+) than with Sr(2+). Carrier (i.e., barite) recycling during water treatment was shown to be effective in enhancing radium removal even after co-precipitation was completed. Calculations based on experimental results show that Ra levels in the precipitate generated in centralized waste treatment facilities far exceed regulatory limits for disposal in municipal sanitary landfills and require careful monitoring of allowed source term loading (ASTL) for technically enhanced naturally occurring materials (TENORM) in these landfills. Several alternatives for sustainable management of TENORM are discussed.

The effects of BaSO4 loading on OPC cementing system for encapsulation of BaSO4 scale from oil and gas industry.

The BaSO4 scales obtained from piping decontamination from oil and gas industries are most often classified as low level radioactive waste. These wastes could be immobilised by stable cement matrix to provide higher safety of handling, transportation, storage and disposal. However, the information available for the effects of the basic formulation such as waste loading on the fundamental properties is still limited. The present study investigated the effect of BaSO4 loading and water content on the properties of OPC-BaSO4 systems containing fine BaSO4 powder and coarse granules. The BaSO4 with different particle size had a marked effect on the compressive strength due to their different effects on hydration products formed. Introduction of fine BaSO4 powder resulted in an increased formation of CaCO3 in the system, which significantly contributed to the compressive strength of the products. Amount of water was important to control the CaCO3 formation, and water to cement ratio of 0.53 was found to be a good level to maintain a low porosity of the products both for fine BaSO4 powder and coarse BaSO4 granule. BaSO4 loading of up to 60 wt% has been achieved satisfying the minimum compressive strength of 5 MPa required for the radioactive wasteforms.

A novel stimuli-synchronized alloy-treated matrix for space-defined gastrointestinal delivery of mesalamine in the Large White pig model.

The study focussed on designing a Stimuli-Synchronized Matrix (SSM) for space-defined colonic delivery of the anti-inflammatory drug mesalamine. The configured matrix provided time-independent delivery and stimuli targeting. Formulations were optimized according to a Box-Behnken experimental design that constituted mesalamine-loaded BaSO4-crosslinked chitosan dispersed within a pectin, carboxymethylcellulose and xanthan gum complex. The complex was compressed into matrices and subsequently alloy-treated with pectin and ethylcellulose. In vitro drug release was determined in the presence and absence of colonic enzymes and the mean dissolution time was used for formulation optimization. To mechanistically elucidate the synchronous catalytic action of the enzymes pectinase and glucosidase on the matrix, computer-aided 3D modelling of active fractions of the enzyme-substrate complexes was generated to predict the orientation of residues affecting the substrate domain. Drug release profiles revealed distinct colonic enzyme responsiveness with fractions of 0.402 and 0.152 of mesalamine released in the presence and absence of enzymes, respectively after 24h. The commercial comparator product showed irreproducible release profiles over the same period (SD=0.550) compared to the SSM formulation (SD=0.037). FTIR spectra of alloy-treated matrices showed no peaks from 1589 to 1512cm(-1) after colonic enzyme exposure. With increasing enzyme exposure there were also no peaks between 1646 and 1132cm(-1). This indicated polymeric enzyme cleavage for controlled and space-defined release of mesalamine. Plasma concentration profiles in the Large White pig model produced a Cmax of 3.77±1.375µg/mL compared to 10.604±2.846µg/mL for the comparator formulation. The SSM formulation proved superior over the comparator product by providing superiorly controlled enzyme-responsive colonic drug delivery.

Mechanoluminescence properties of gamma-ray-irradiated BaSO4:Eu phosphors.

BaSO(4) activated with various concentrations of Eu were prepared by solid-state reaction technique. Thermoluminescence (TL) and mechanoluminescence (ML) of γ-ray-irradiated BaSO(4):Eu(2)O(3) phosphors were recorded. In the TL glow curve of the phosphor a single peak at 170°C was observed. The TL of the phosphors were also recorded after deforming the phosphors by dropping a piston of mass 0.4 kg onto them with different impact velocities. TL intensity (after deformation) decreased with increasing the impact velocity. In the ML intensity vs time curve two peaks were observed. ML intensity increased with increasing impact velocity of the piston and the time corresponding to peak ML intensity shifted to a shorter time value. ML intensity decreased drastically when it was recorded after annealing the sample at 170°C. The BaSO(4) phosphors activated with 0.1 mol% of Eu(2)O(3) showed optimum TL and ML. The photoluminescence emission spectrum of the sample showed that Eu enters as Eu(2+) ion in host lattice.

New modified expressions for isothermal decay of Teflon embedded LiF:Mg,Cu,P and BaSO4:Eu phosphors.

This paper gives a full mathematical description of the kinetics expressions used in thermoluminescent isothermal decay experiments. The corresponding equations have been slightly modified considering the peak intensity at the maximum (I(M)) instead of the peak area Φ as proportional to absorbed dose, given normally in isothermal decay equations. The isothermal decay method was applied to the principal glow peaks of two different phosphors: LiF:Mg,Cu,P+PTFE, using first- and second-order kinetics, and BaSO(4):Eu+PTFE, using second-order kinetics.

Estimation of bioavailability of metals from drilling mud barite.

Drilling mud and associated drill cuttings are the largest volume wastes associated with drilling of oil and gas wells and often are discharged to the ocean from offshore drilling platforms. Barite (BaSO4) often is added as a weighting agent to drilling muds to counteract pressure in the geologic formations being drilled, preventing a blowout. Some commercial drilling mud barites contain elevated (compared to marine sediments) concentrations of several metals. The metals, if bioavailable, may harm the local marine ecosystem. The bioavailable fraction of metals is the fraction that dissolves from the nearly insoluble, solid barite into seawater or sediment porewater. Barite-seawater and barite-porewater distribution coefficients (Kd) were calculated for determining the predicted environmental concentration (PEC; the bioavailable fraction) of metals from drilling mud barite in the water column and sediments, respectively. Values for Kdbarite-seawater and Kdbarite-porewater were calculated for barium, cadmium, chromium, copper, mercury, lead, and zinc in different grades of barite. Log Kdbarite-seawater values were higher (solubility was lower) for metals in the produced water plume than log Kdbarite-porewater values for metals in sediments. The most soluble metals were cadmium and zinc and the least soluble were mercury and copper. Log Kd values can be used with data on concentrations of metals in barite and of barite in the drilling mud-cuttings plume and in bottom sediments to calculate PECseawater and PECsediment.

Interactions of pigments and opacifiers on color stability of MDX4-4210/type A maxillofacial elastomers subjected to artificial aging.

STATEMENT OF PROBLEM: The color instability and degradation of maxillofacial elastomers limit the function and cosmetic quality of facial prostheses. PURPOSE: The purpose of this study was to measure the interactions of oil pigments plus dry earth opacifiers at 5%, 10%, and 15% by volume in stabilizing the color of MDX4-4210/type A silicone elastomers before and after artificial aging. MATERIAL AND METHODS: In the first part of the study, each of 5 opacifiers (Georgia kaolin powder neutral, kaolin powder calcined, Artskin white, dry pigment titanium (Ti) white, or Ti white artists' oil color) at 10% concentrations were combined with each of 5 oil pigment types (no pigment, cadmium-barium red deep, yellow ochre, burnt sienna, or a mixture of the 3 pigments), for a total of 25 experimental groups of elastomers. In the second part of the study, 50 experimental groups of elastomers were made by combining 1 of 5 opacifiers at 5% and 15% concentrations with 1 of 5 oil pigments as in Part 1. Five specimens of each elastomer were tested, for a total of 375 specimens. In each part of the study, all specimens were aged in an artificial aging chamber. CIE L*a*b* values were measured by a spectrophotometer. The color differences (DeltaE*) were subjected to repeated-measures analysis of variance. Mean values were compared by Tukey-Kramer intervals (alpha = .05). RESULTS: In Part 1, when the opacifiers were tested at 10% concentration, Ti white oil color had the most color change, and dry pigment Ti white had the least; all other opacifiers were not significantly different from each other. In Part 2, at 5%, Ti white oil color had the most color change; all other opacifiers were not significantly different from the others. At 15%, Ti white oil color again had the most color change, followed by Artskin white, kaolin powder calcined, and Georgia kaolin; Ti white dry earth pigment had the least color change. Overall, 5% Artskin white had less color change than the 15%, whereas 15% dry pigment Ti white had less color change than the 5% (P < .001). The 5% and 15% of other opacifiers were not significantly different. CONCLUSIONS: At all 3 concentrations, oil pigments mixed with opacifiers helped protect the MDX4-4210/type A silicone elastomer from color degradation over time. Dry pigment Ti white remained the most color stable over time, followed by the pigments mixed with kaolin powder calcined, Georgia kaolin, Artskin white, and Ti white artists' oil color.

Joint analyses by laser-induced breakdown spectroscopy (LIBS) and Raman spectroscopy at stand-off distances.

Raman spectroscopy and laser-induced breakdown spectroscopy (LIBS) of solid samples have both been shown to be feasible with sample-to-instrument distances of many meters. The two techniques are very useful together, as the combination of elemental compositions from LIBS and molecular vibrational information from Raman spectroscopy strongly complement each other. Remote LIBS and Raman spectroscopy spectra were taken together on a number of mineral samples including sulfates, carbonates and silicates at a distance of 8.3 m. The complementary nature of these spectra is highlighted and discussed. A factor of approximately 20 difference in intensity was observed between the brightest Raman line of calcite, at optimal laser power, and the brighter Ca I LIBS emission line measured with 55 mJ/pulse laser power. LIBS and Raman spectroscopy have several obstacles to devising a single instrument capable of both techniques. These include the differing spectral ranges and required detection sensitivity. The current state of technology in these areas is discussed.

Effect of hyperbaric oxygen treatment on incorporation of an autogenous cancellous bone graft in a nonunion diaphyseal ulnar defect in cats.

OBJECTIVE: To determine whether hyperbaric oxygen treatment (HBOT) would affect incorporation of an autogenous cancellous bone graft in diaphyseal ulnar defects in cats. ANIMALS: 12 mature cats. PROCEDURE: Bilateral nonunion diaphyseal ulnar defects were created in each cat. An autogenous cancellous bone graft was implanted in 1 ulnar defect in each cat, with the contralateral ulnar defect serving as a nongrafted specimen. Six cats were treated by use of hyperbaric oxygen at 2 atmospheres absolute for 90 minutes once daily for 14 days, and 6 cats were not treated (control group). Bone labeling was performed, using fluorochrome markers. Cats were euthanatized 5 weeks after implanting, and barium sulfate was infused to evaluate vascularization of grafts. Ulnas were evaluated by use of radiography, microangiography, histologic examination, and histomorphometric examination. RESULTS: Radiographic scores did not differ between treatment groups. Microangiographic appearance of grafted defects was similar between groups, with all having adequate vascularization. Differences were not observed between treated and nontreated groups in the overall histologic appearance of decalcified samples of tissue in grafted defects. Mean distance between fluorescent labels was significantly greater in cats given HBOT than in nontreated cats. Median percentage of bone formation in grafted defects was significantly greater in cats given HBOT. CONCLUSIONS: Hyperbaric oxygen treatment increased the distance between fluorescent labels and percentage of bone formation when incorporating autogenous cancellous bone grafts in induced nonunion diaphyseal ulnar defects in cats, but HBOT did not affect revascularization, radiographic appearance, or qualitative histologic appearance of the grafts.

Oral contrast agents for CT: a taste test survey.

PURPOSE: Our goal was to evaluate the palatability of the currently available oral contrast agents for CT. METHOD: We surveyed 202 adults (92 women and 110 men) with a mean age of 59 years. Each participant sampled five or eight products. The participants ingested 1 oz. of each product and recorded an overall score, taking into account the factors of palatability that were important to them. Scores were marked on a visual analog rating scale with 0 representing "dislike a lot" and 10 representing "like a lot." RESULTS: The following mean palatability scores were obtained: Gastrografin mixed with Tropical Punch Kool-Aid 8.2; Scan C 5.7; Cheetah 4.7; Readi-Cat 4.4; E-Z-Cat 4.0; Tomo-Cat 3.6, Prep-Cat 3.5; Baro-Cat 3.2; Lipomul mixed with water 3.1. CONCLUSION: Statistical cluster analysis suggested the following groupings of the products (i.e., products with statistically similar scores grouped together): Cluster 1-Kool-Aid with Gastrografin; Cluster 2-Scan C, Cheetah, Readi-Cat: Cluster 3-E-Z-Cat, Tomo-Cat, Prep-Cat, Baro-Cat, Lipomul.